Halobetasol 0.01%/Tazarotene 0.045% Lotion in the Treatment of Moderate-to-Severe Plaque Psoriasis: Maintenance of Therapeutic Effect After Cessation of Therapy

Background: Psoriasis is a chronic, immune-mediated disease that varies widely in its clinical expression. Topical corticosteroids (TCS) are the mainstay of treatment. Long-term safety remains a concern, limiting use, and posttreatment flare is common. Tazarotene has also been shown to be effective in psoriasis, with efficacy maintained several weeks posttreatment. Fixed combination therapy with TCS and tazarotene may improve psoriasis signs and minimize posttreatment flare or rebound. Objective: To investigate the maintenance of effect posttreatment with a once-daily application of halobetasol propionate 0.01 %/tazarotene 0.045% (HP/TAZ) lotion in comparison with its active ingredients and vehicle in patients with moderate-to-severe plaque psoriasis. Methods: Multicenter, randomized, double-blind, vehicle-controlled Phase 2 study in moderate or severe psoriasis (N=212). Patients randomized (2:2:2:1 ratio) to receive HP/TAZ, individual active ingredients, or vehicle, once-daily for 8 weeks with a 4-week posttreatment follow-up. Efficacy assessments included treatment success (defined as at least a 2-grade improvement from baseline in the IGA score, and 'clear' or 'almost clear'), and impact on individual signs of psoriasis (erythema, plaque elevation, and scaling) at the target lesion. Results: At the end of the 4-week posttreatment period, 38.2% of patients who had been treated with HP/TAZ were treatment successes; compared with 21.0%, 12.8% and 6.9% of patients who had been treated with HP (P=0.042), TAZ (P=0.004), or vehicle (P=0.002). HP/TAZ lotion was also superior in maintaining reductions in psoriasis signs of erythema, plaque elevation, and scaling at the target lesion. At the end of the 4-week posttreatment period, 49.1%, 54.5%, and 54.5% of patients, respectively, were treatment successes: compared with 38.7% (P=0.26), 48.4% (P=0.51), and 48.4% (P=0.51) of patients who had been treated with HP; 29.8% (P=0.049), 31.9% (P=0.022), and 23.4% (P=0.001) who had been treated with TAZ; and 13.8% (P=0.002), 20.7% (P=0.003), and 20.7% (P=0.003) who had been treated with vehicle. Side effects were minimal and tended to resolve during the posttreatment period. Conclusions: In conclusion, HP 0.01 %/TAZ 0.045% lotion provides synergistic efficacy following 8 weeks' therapy that is sustained after a 4-week posttreatment period.